The Cerveny CBB 693-4PRX Kaiser 4 Valve BBb Tuba is a very large 4/4 size instruments and puts out an equally large amount of sound. It features a .835-inch bore, nickel-silver leadpipe, and 19.7-inch bell with nickel-silver bell ring which adds some body to the tone. In addition, anti-corrosive nickel-silver is used for the valve casings and slides.The Cerveny tubas have always been known for their beautiful sound and excellent rotary valves. Th...